• by Mark Walsh  @markfwal, October 15, 2012

Last month, Facebook rolled out Custom Audience ads, allowing marketers to retarget existing customers on the site through contact information such as email addresses and phone numbers. In one of the early campaigns using custom audience targeting on Facebook, a large travel client generated $25 in room-booking revenue for every $1 spent on advertising, according to Facebook ad specialist AdParlor.

The firm said the travel company used its existing email database of people who had previously stayed at one of their hotels to target them on Facebook. “This is further proof that Facebook can innovate with their advertising products to drive ROI positive ad spend and we expect more companies to begin leveraging this new targeting feature,” said AdParlor CEO Hussein Fazal, in a statement.

The AdParlor release follows examples provided by Facebook itself last week meant to demonstrate the effectiveness of Custom Audience ads involving a pair of e-commerce companies. One targeted its email list on Facebook, increasing its sign-up conversion rate by 43%, and other, OpenSky, improved its conversion rate by 30%.